Angiolymphoid hyperplasia with eosinophilia.

We report a case of angiolymphoid hyperplasia with eosinophilia (ALHE). Histologically, some vessels were lined with plump endothelial cells. Infiltration by lymphocytes, histiocytes and eosinophils was marked. An arteriovenous malformation and vessels occluded by endothelial cell hyperplasia were present. PCNA staining gave positive results for the nuclei of many of the plump endothelial cells. Electron-microscopic findings disclosed increased metabolic activity in the cells. These observations suggest that the plump endothelial cells, characteristic of ALHE, have high metabolic activity. These results suggest that blood flow is increased by arteriovenous malformations and that blood pressure is elevated by occlusion, resulting in hyperplasia of plump endothelial cells and accelerated neovascularization.